A couple of things
1. I downgraded from the micro iDSD Signature which to my ears is a better sounding device. To me, it sounds better than the Mojo 1 & Gryphon.
2. I got used to not having to use balanced cables with Mojo & Signature but with the Gryphon, there's not enough power and image separation with Single-Ended Output so I'm forced to use 4.4 Out for best sound.
3. It did not power my planars well, I was easily reaching above 90 on volume even with Balanced Out which meant the headroom was not great either. Same story when using something like Meze 99C or P1 with Single-Ended Output, I was reaching 80/100 on volume.
4. I thought I'd get more use out of Bluetooth, but Gryphon is still a big device and I don't use Headphones while on the go, so carry a bigger device outside did not make much sense. My previous Bluetooth DACs like BTR5, xCAN, XA-10, BC3... were easier to carry. If I ever need it, I'll probably get the BTR7 instead for Bluetooth, I'm happy with my LG G8x for portable use so....
There are other things like less battery life (compared to Signature), price (IMO it's over priced) but above ones are the main reasons I sold it. Kind of depends on your taste I guess, it's still a good sounding device, If you want something to kick back and relax, it'll give you a nice laid back sound without sacrificing on details and a decently wide soundstage. I'm familiar with Mojo, to my ears it had an opposite sound signature, more intense, a lot of detail, in a non-fatiguing way but still very attention garbing, intimate but more precise imaging, no distortion (Gryphon has it at higher volumes). I'm guessing Mojo 2 will have a similar sound signature but with a few improvements overall.
I read about G5, seems like a good device that ticks all the boxes for a powerful portable DAC. I might give either the G5 or Colibri a try next.